1. Field of the Invention
The present invention relates to a controller apparatus for driving a motor in an electrically powered automotive vehicle, or an electric vehicle for short, that is used to drive such electric vehicle and, more particularly, to the controller apparatus for the electric vehicle of a kind, in which a controller or a component part incorporated therein is provided in a plural number to have a redundancy.
2. Description of Related Art
Electric vehicles are available in various types including, inter alia, the type that is driven solely by an electrically powered drive motor or the hybrid type that is driven by a concurrent use of the electrically powered drive motor and the internal combustion engine. In those electric vehicles, the manner of installation of the electric drive motor includes an in-wheel motor system, in which the electric drive motor is installed inside each of the vehicle wheels, and a system in which the electric drive motor mounted on the vehicle body is distributed by means of a differential. Whatever the particular manner of installation of the electric drive motor is employed, the use is generally made of a controller made up of a control circuit unit and a power circuit unit, in addition to a higher control means for generating a motor drive command from information on, for example, a handlebar and/or an accelerator.
In discussing the prior art pertinent to the present invention, reference will be made the in-wheel motor system in the following description. FIG. 16 of the accompanying drawings schematically illustrates the conventional in-wheel motor driving system, which includes a wheel support bearing unit A for rotatably supporting a vehicle wheel W, an electric drive motor B, and a reduction gear unit C for reducing the number of revolutions, i.e., the rotational speed, of the drive motor B and then transmitting the reduced rotational speed of the drive motor B to an inner member 2, that is a rotatable ring of the wheel support bearing unit A, all operatively associated with each other to form the in-wheel motor drive mechanism that is an assembly. The drive motor B is controlled by a controller 53 in response to a motor drive command a outputted from, for example, an electric control unit (ECU). The controller 53 is made up of a control circuit unit 54, which is a light electric circuit (a low voltage circuit or a low current circuit), and a power circuit unit 55 which is a heavy electric circuit.    [Patent Document 1] JP Laid-open Patent Publication No. 2008-168790    [Patent Document 2] JP Laid-open Patent Publication No. 2008-172975